Bipolar devices in state of the art circuits are used in complementary pairs, and, in high voltage circuits, are typically combined with complementary high voltage DMOS devices in the same IC. It is important that these device species be isolated, and the fabrication sequence for the different types of devices be compatible. It is highly desirable that the fabrication sequence be largely the same for each species of device. It will be appreciated by those skilled in the art that this process compatibility places severe limitations on the design and processing of the different species of devices. One of the designs of choice for bipolar devices is a buried collector structure with a vertical current flow. Vertical DMOS devices are also desirable from the standpoint of reducing device area on the chip. However to date it has been difficult to make vertically configured efficient complementary bipolar and isolated complementary DMOS devices on the same chip with a compatible process technology. In prior art processes for making vertical isolated DMOS devices the drift region of the DMOS device is typically made in an epitaxial layer with a uniform doping gradient in the vertical dimension. Graded doping of the drift region toward the drain is desirable but can only be implemented easily in a lateral device configuration. Vertical retrograde doped drift regions can be made, but typically with significant cost and difficulty.